<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    //const obj={}
    //obj.props=100
    //console.log(obj);//100
    //obj.props = 200
    //console.log(obj);//200
    //obj={} //报错，不能再重新赋值地址(变量不能再变为常量)
    //console.log(obj);
    const arr=[]
    arr.push("abc")
    arr.length = 0
    console.log(arr);
    arr=[] //报错，变量不能再变为常量
</script>
</html>